Help in writing an ANT task.

Currently my project uses Maven for build. But now we want to use Ant for the build purposes. We now have a requirement to write an Ant task to take the update of the jar files using Maven whenever Ant build file is run.
Please help me in writing an ANT task for the same.

Note: On my own I searched the net and tried to implement it but didn't get much success.

That seems like an odd requirement. Most people go from Ant to Maven and not vice versa. Also, your requirement says that you still want to use the Maven repository for your Ant build. It's not impossible though to do what you want. I just wonder what Ant + Maven repo buys you over Maven. And whether it could be better accomplished via having Ant code in your Maven pom.

On to your question. You can use dependency:get in order to pull jars without having a Maven POM. For example:
mvn -DgroupId=com.group -DartifactId=the-jar -Dversion=1.0.0 dependency:get

Which means you can write an Ant task that loops through a desired list of jars and uses <exec> to run Maven commands.

Alternatively, you could create a pom.xml for your dependencies, run it and then copy over the jars (via the assembler plugin) into your Ant build.